At the NTEA Work Truck Week 2025, Kenworth showed the Cummins B6.7 Octane engine for the first time. The new gasoline engine will be EPA 2027 certified, will meet strict CARB low NOx regulations. It will be available for order later this year in Kenworth’s line of Class 5-7 conventional trucks.

Diesel-Like Performance

Kenworth said the Cummins gasoline engine provides diesel-like performance with horsepower ranging from 200-300hp with up to 660 lb.-ft. of torque. 

The engine will be paired with the Paccar TX-8 automated transmission. 

According to Cummins, the engine is 10% more fuel efficient than other gasoline engines in its category, and it has an extended oil drain interval of up to 15,000 miles.

“The engine was validated against the same standards as Cummins diesel B6.7 engine,” said Kevin Haygood, Kenworth assistant general manager for sales and marketing. “With environmental regulations changing, it spurred us to offer another engine option to our customers. The new Cummins B6.7 Octane engine will meet stringent emission regulations, so we expect it to be a popular option in California and other states that have adopted CARB’s standards. It can be a great fit for many of our customers’ applications, especially in P&D, and towing applications. We also see it being popular for the lease and rental markets, as well as for landscapers, where those behind the wheel are used to driving gas-powered vehicles.”

Better Emissions Control

According to Haygood, the B6.7 Octane engine simplifies maintenance. 

“There is no need for DEF and active regens with this engine since Cummins utilizes a 3-way catalyst for emission control,” he said. “What’s more, body builders will not have a problem with the engine or placement with the fuel tank (45-80 gallon options) which will streamline upfits.” 

Haygood said new markets may also emerge for Kenworth thanks to the new engine. 

“Some fleets that run Class 5-6 trucks run an all-gasoline fleet and their maintenance facilities are set up for that,” he added. “By spec’ing the Cummins B6.7 Octane engine, new customers can step into a Kenworth and enjoy all the driver comfort and longevity a Kenworth offers while keeping their operations simplified with a gasoline powerplant.”